The embodiments disclosed herein relate generally to a system, an apparatus, and/or a method for filtering and/or separating particles. More specifically, embodiments disclosed herein relate to a system, an apparatus, and/or a method for repairing damaged sifter screens using plugs with a mesh layer.
Sifter screens are used to filter particles in industrial filtration systems. Different sizes and/or types of particles may be separated using filter screens in a vibratory separator. In the oil and gas industry, for example, shale shakers use filter screens to separate drill cuttings from drilling fluid in on-shore and/or off-shore oilfield drilling. The sifter screens have a wire mesh fixed across a frame. The frame has a rectangular grid of support ribs that divide the frame into an orthogonal array of cells. The mesh is secured to the ribs as well as to the surrounding frame. To promote separation, vibrational and/or circular motion is applied to the sifter screen.
The wire mesh has different mesh sizes defined by the size of the apertures between the individual wires in the mesh. The size of the apertures of the mesh is selected depending on the size of the particle to be filtered. Particles smaller than the aperture pass through the wire mesh and/or through the cells between the ribs. The remaining particles are discharged at an end of the filter screen. The discharged particles are collected in a bin and/or a pit. The particles and/or fluid that pass through the mesh are collected in a pan and/or a sump below the sifter screen. The particles and/or fluid that pass through the mesh may also pass through a secondary processing system, such as a degasser.
Over the life of the filter screen, the particles cause wear on the wire mesh. Because of the cellular structure, the strain and/or damage experienced by the mesh is isolated over each cell. Damage causes a breach in the mesh in one or more of the small unsupported areas between the cells. As a result, that area of the mesh allows larger particles to pass through than desired. Once the damage occurs, the screen must be replaced or repaired. Certain regions of the mesh are more prone to damage than other regions. For example, the mesh stretched across cells below where the particles are introduced experience greater wear than the mesh stretched across cells towards the exit end of the screen.
To extend the operational life of the screen, the cell with the damaged mesh may be blocked by epoxy or other plastic or resin based material. Alternatively, solid plugs may be installed into the cell to block particles from going through damaged wire mesh. These solid plugs fit into the cells and have a solid surface oriented towards the damaged mesh. The solid plugs fit into the cell from below and are hammered into place. As such, these solutions are designed to block particles from traveling through the damaged screen and/or the cell. Therefore, the cells with the epoxy or solid plugs no longer filter particles.
The solid plugs cannot be reused as they are hammered in place without a way to remove them. As more of the plugs are installed into more of the cells, the filtering ability of the filter screen is reduced. As more solid plugs are installed, the filter screen must eventually be replaced. When the filter screen is discarded, the installed plugs are also discarded.